The truth about government spending and the carbon tax

Since World War II, there has been more than 30 major changes to the tax code. These changes have had a dramatic impact on the economy and, one would expect, on government revenues. Except in reality, they have not. A recent study by the R Street Institute found that demand for government spending drives tax policy, not the other way around. This conclusion has important implications for the carbon tax debate.

There have been numerous tax rate changes in the past 70 years, with the marginal income tax rate falling from a high of over 90 percent in the 1950s to as low as 28 percent in the late 1980s. Yet during this entire time period, federal tax revenue has stayed in a fairly narrow band when measured as a percentage of gross domestic product, never rising above 20 percent or falling much below 15 percent between 1950 and 2018.

What the R Street Institute study found is the belief that any kind of new taxation introduces even greater government spending is based on very little actual evidence. Instead, Hauser’s law provides evidence that certain kinds of tax swaps, such as exchanging an income tax for a carbon tax, may actually increase the rate of economic growth without increasing the tax share of the overall economy. This means that taxing pollution more and taxing income less could boost economic growth, keep spending from outstripping revenues, and help clean up the environment.

The primary reason for the increase in government spending over the past century or so has been the stealthy structure of the modern income tax. When the Seventeenth Amendment passed in 1913, the federal income tax started at a low rate that only applied to a small percentage of wealthy households and excluded large portions of the population. This made it possible to rapidly expand the tax to cover more individuals by simply lowering the income threshold, which was made easier for lawmakers after Congress declared war in 1917 and then again in 1941. Before 1913, federal revenues made up only about 5 percent of annual gross domestic product, compared to the level of just under 18 percent last year.

The relative imperviousness of the gross domestic product tax percent equilibrium since the late 1940s suggests that spending pressures drive taxes and not the other way around. This is important when considering whether to replace an income tax with other kinds of taxes, such as a carbon tax. Since the goal of a carbon tax is to discourage emissions, most carbon tax proposals apply the tax to almost all emissions from the beginning. This leaves no room for additional political exploitation or increase as tax brackets remain unchanged to account for inflation.

Moreover, unlike revenue from income, sales, or property taxes, which all tend to increase over time at a constant rate, revenue from a carbon tax is likely to remain stable or fall gradually as emissions decline. Why? This is because the tax is on pollution, which can be substituted quickly through changes in behavior and improvement in energy technology. The higher the tax, the faster the fall in revenues. This means that distinguishing between tax structures and whether they boost or depress economic growth is very important and independent of government spending.

It is not as though the budget problems of the United States are going away any time soon. The national debt is currently more than $21 trillion. Moreover, thanks to the Republican tax cuts, the federal budget deficit is expected to increase from $665 billion in 2017 to more than $1 trillion a year by 2021, according to Politifact. Different tax regimes matter to the health of the republic in the 21st century. False assumptions on taxes and spending should not be allowed to remain unquestioned for decades.